Kernel/LibC: Implement getpeername

kernel/kernel/FS/Inode.cpp

@@ -186,6 +186,14 @@ namespace Kernel
 		return getsockname_impl(address, address_len);
 	}
 
+	BAN::ErrorOr<void> Inode::getpeername(sockaddr* address, socklen_t* address_len)
+	{
+		LockGuard _(m_mutex);
+		if (!mode().ifsock())
+			return BAN::Error::from_errno(ENOTSOCK);
+		return getpeername_impl(address, address_len);
+	}
+
 	BAN::ErrorOr<size_t> Inode::read(off_t offset, BAN::ByteSpan buffer)
 	{
 		LockGuard _(m_mutex);

kernel/kernel/Networking/TCPSocket.cpp

@@ -256,6 +256,17 @@ namespace Kernel
 		return to_send;
 	}
 
+	BAN::ErrorOr<void> TCPSocket::getpeername_impl(sockaddr* address, socklen_t* address_len)
+	{
+		if (!m_has_connected && m_state != State::Established)
+			return BAN::Error::from_errno(ENOTCONN);
+		ASSERT(m_connection_info.has_value());
+		const size_t to_copy = BAN::Math::min(m_connection_info->address_len, *address_len);
+		memcpy(address, &m_connection_info->address, to_copy);
+		*address_len = to_copy;
+		return {};
+	}
+
 	bool TCPSocket::can_read_impl() const
 	{
 		if (m_has_connected && !m_has_sent_zero && m_state != State::Established && m_state != State::Listen)

kernel/kernel/Networking/UNIX/Socket.cpp

@@ -412,4 +412,33 @@ namespace Kernel
 		return nread;
 	}
 
+	BAN::ErrorOr<void> UnixDomainSocket::getpeername_impl(sockaddr* address, socklen_t* address_len)
+	{
+		if (!m_info.has<ConnectionInfo>())
+			return BAN::Error::from_errno(ENOTCONN);
+		auto connection = m_info.get<ConnectionInfo>().connection.lock();
+		if (!connection)
+			return BAN::Error::from_errno(ENOTCONN);
+
+		sockaddr_un sa_un;
+		sa_un.sun_family = AF_UNIX;
+		sa_un.sun_path[0] = 0;
+
+		{
+			SpinLockGuard _(s_bound_socket_lock);
+			for (auto& [path, socket] : s_bound_sockets)
+			{
+				if (socket.lock() != connection)
+					continue;
+				strcpy(sa_un.sun_path, path.data());
+				break;
+			}
+		}
+
+		const size_t to_copy = BAN::Math::min<socklen_t>(sizeof(sockaddr_un), *address_len);
+		memcpy(address, &sa_un, to_copy);
+		*address_len = to_copy;
+		return {};
+	}
+
 }

kernel/kernel/Process.cpp

@@ -1284,6 +1284,20 @@ namespace Kernel
 		return 0;
 	}
 
+	BAN::ErrorOr<long> Process::sys_getpeername(int socket, sockaddr* address, socklen_t* address_len)
+	{
+		LockGuard _(m_process_lock);
+		TRY(validate_pointer_access(address_len, sizeof(address_len), true));
+		TRY(validate_pointer_access(address, *address_len, true));
+
+		auto inode = TRY(m_open_file_descriptors.inode_of(socket));
+		if (!inode->mode().ifsock())
+			return BAN::Error::from_errno(ENOTSOCK);
+
+		TRY(inode->getpeername(address, address_len));
+		return 0;
+	}
+
 	BAN::ErrorOr<long> Process::sys_getsockopt(int socket, int level, int option_name, void* option_value, socklen_t* option_len)
 	{
 		LockGuard _(m_process_lock);